177Lu-prostate specific membrane antigen(PSMA)radio-ligand therapy has been approved abroad for advanced prostate cancer and has been in several clinical trials in China.Based on domestic clinical practice and experimental data and referred to international experience and viewpoints,the expert group forms a consensus on the clinical application of 177Lu-PSMA radio-ligand therapy in prostate cancer to guide clinical practice.

Objective:To explore the clinical pathological characteristics and initial 131I curative responses of familial differentiated thyroid cancer (FDTC) and sporadic differentiated thyroid cancer (SDTC). Methods:A total of 66 FDTC patients (19 males, 47 females, age (39.8±11.7) years) and 1 701 SDTC patients (442 males, 1 259 females, age (40.9±11.3) years) who underwent 131I therapy in Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 2010 and August 2018 were retrospectively enrolled. The clinical pathological characteristics, preablative stimulated thyroglobulin (ps-Tg), preablative stimulated thyroglobulin antibody (ps-TgAb) and response to initial therapy (excellent response, indeterminate response, biochemical incomplete response, structural incomplete response) of two groups were analyzed and compared. The clinical pathological parameters included age, gender, pathological type, tumour maximum diameter, bilateral, multifoci, nodules goiter, thyroiditis, thyroid membrane invasion, lymph node metastasis (LNM), invasion of the surrounding soft tissues, distant metastasis, TNM staging and American Thyroid Association (ATA) risk stratification (low-risk, intermediate-risk, high-risk). χ2 test or Fisher exact test and independent-sample t test were used to compare the data between two groups. Results:Comparing with SDTC group, FDTC group showed higher proportion of bilateral foci (45.5%(30/66) vs 31.2%(530/1 701); χ2=5.999, P=0.010), thyroid membrane invasion (43.9%(29/66) vs 26.6%(452/1 701); χ2=9.672, P=0.002) and distant metastasis (15.2%(10/66) vs 6.2%(105/1 701); χ2=8.418, P=0.004). There was a statistical difference in risk stratification between two groups (high-risk: 18.2%(12/66) vs 9.2%(156/1 701); intermediate-risk: 68.2%(45/66) vs 72.7%(1 237/1 701); low-risk: 13.6%(9/66) vs 18.1%(308/1 701); χ2=6.898, P=0.030). But the tumor maximum diameter of FDTC group was smaller than that of SDTC group ((1.24±0.74) vs (1.50±0.92) cm; t=-2.275, P=0.020). There were no significant differences in other clinical pathological parameters between FDTC group and SDTC group ( t=-0.804, χ2 values: 0.101-5.359, all P>0.05). There were no significant differences between two groups in the postoperation ps-Tg, ps-TgAb levels and the response to initial therapy after 131I treatment ( χ2 values: 0.059-1.915, all P>0.05). Conclusions:The FDTC group displays distinct characteristics as increased aggressiveness at diagnosis. But after accurately treatment, there is no significant difference in the response to therapy between two groups.

The poor prognosis of refractory thyroid cancer is the critical factor affecting the survival of patients with thyroid cancer. At present, multi-kinase inhibitors, surgery, particle implantation and other therapeutic methods are commonly used in clinical practice, which can improve the prognosis of patients to some extent, but the overall efficacy is still unsatisfactory. In recent years, immunotherapy has shown high efficacy, safety and reliability in the treatment of many tumors. In this article, the mechanism, current situation, method and prospect of immunotherapy in patients with refractory thyroid cancer are presented.

At the end of December 2019, acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China. Different from radiology examinations, the protocols of nuclear medical imaging examinations are complicated, in which more workplaces and staff are needed, resulting more complex management of patients and higher protection requirements. Combined with the characteristics of SPECT and PET imaging procedures, this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected noval coronavirus infec- tion. The main purpose is to protect medical staff from virus infection, effectively reduce the risk of virus transmission during the examination process, and ensure the medical quality and safety.

At the end of December 2019, acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China. Different from radiology examinations, the protocols of nuclear medical imaging examinations are complicated, in which more workplaces and staff are needed, resulting more complex management of patients and higher protection requirements. Combined with the characteristics of SPECT and PET imaging procedures, this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected novel coronavirus infection. The main purpose is to protect medical staff from virus infection, effectively reduce the risk of virus transmission during the examination process, and ensure the medical quality and safety.

Objective:To investigate the correlation between 131I uptake and therapeutic efficacy in metastatic differentiated thyroid carcinoma (DTC). Methods:The clinical data of 138 patients with metastatic DTC (42 males, 96 females, age range: 8-74 years) treated with 131I in nuclear medicine departments of 31 centers all over China were retrospectively analyzed. The lesional 131I uptake was quantitatively analyzed with target-to-nontarget (T/NT) ratio through the regions of interest in metastatic lesions confirmed by either planar or tomographic 131I SPECT/CT imaging. The efficacies of 131I treatment on the metastatic DTC were divided into complete remission (CR), partial remission (PR), stable disease (SD) and progress disease (PD) based on the change of the lesion diameter before and after the treatment. Factors which may affect therapeutic efficacy were assessed by the univariate (Kruskal-Wallis rank sum test, χ2 test and one-way analysis of variance) and binary logistic regression analyses. The receiver operating characteristic (ROC) curve of lesional T/NT ratio to predict the ineffectiveness of 131I therapy was performed. Results:A total of 1 165 efficacies were evaluated. The planar imaging results ( n=653) showed that there was no statistically significant difference of T/NT ratio among CR, PR, SD and PD groups ( χ2=4.15, P>0.05). The tomographic imaging results ( n=512) suggested CR, PR, SD and PD in 7.6%(39/512), 65.8%(337/512), 22.9%(117/512), and 3.7%(19/512) of individuals, respectively, and the T/NT ratio among the four groups was significantly different ( χ2=30.46, P<0.01). The univariate analysis also showed that age, stimulated thyroglobulin(sTg), 131I dose were the factors affecting therapeutic efficacy ( F or χ2 values: 2.561, 7.095 and 8.799, all P<0.05). Furthermore, binary logistic regression analysis revealed that older patients (odds ratio ( OR)=1.034, P=0.022) or patients with lower lesional T/NT ( OR=1.086, P=0.006) had a higher probability of ineffectiveness. The area under ROC curve for T/NT ratio to predict ineffectiveness was 0.726, and the cut-off value was 6.2, with a sensitivity of 78.7%(107/136) and a specificity of 73.1%(275/376). Conclusions:131I therapy is an effective treatment for metastatic DTC. The age at the time of metastatic diagnosis and the lesional T/NT ratio are independent influential factors for ineffectiveness of 131I therapy. When the leisonal T/NT ratio is lower than 6.2, the inefficiency of 131I is higher.

Objective:To evaluate the effects of different sphere volumes, target background ratio (T/B) and post-processing correction techniques on the quantitative results of 99Tc m SPECT/CT. Methods:Six spheres with different diameters (37, 28, 22, 17, 13, 10 mm) in National Electrical Manufacturers Association International Electrotechnical Commission (NEMA IEC) models were filled with a mixture of 0.54 MBq/ml 99Tc m and iodixanol. The mixture iodine content was about 0.3%(135 mg), which led to different T/B (32∶1, 16∶1, 8∶1, 4∶1) by changing the radioactivity concentration of the cylinder. Routine imaging was performed on different T/B phantoms which were scanned by SPECT/CT. The CT threshold method was used for the delineation of volume of interest (VOI). Then the same processing correction technique and ordered-subsets expectation maximization (OSEM) parameters were used to calculate the radioactivity concentrations of different spheres, and further compared with the true values, and the accuracies were calculated. Pearson correlation analysis was applied to evaluate the relationships between sphere volume, T/B and quantitative results. The sphere with T/B of 32∶1 and diameter of 37 mm were processed by 3 correction techniques (CT attenuation correction (CTAC)+ scatter correction (SC)+ resolution recovery (RR); CTAC+ SC; CTAC+ RR). One-way analysis of variance and the least significant difference t test were used to analyzed the effects of 3 correction techniques on the quantitative results and image contrasts. Results:There were significant relationships between the sphere volumes, T/B and the quantitative accuracy ( r values: 0.757, 0.409, both P<0.05). There were significant differences of 3 correction techniques on the quantitative results and image contrast ( F values: 139.665 and 38.905, both P<0.001). Among them, the quantitative error of CTAC+ SC+ RR was lower than that of CTAC+ SC ((9.63±8.82)% vs (38.89±2.17)%; P<0.001), and similar to that of CTAC+ RR ((8.70±6.64)%; P>0.05). The quantitative error of CTAC+ RR was lower than that of CTAC+ SC ( P<0.001). The image contrast of CTAC+ SC+ RR was higher than that of CTAC+ SC ((93.45±0.91)% vs (92.41±0.25)%; P<0.001) and the image contrast of CTAC+ SC was higher than that of CTAC+ RR ((91.37±0.87)%; P<0.001). Conclusions:The larger sphere volume and the higher T/B, the more quantitative accuracy. The volume has a more significant effect on quantitative accuracy than T/B. Choosing the appropriate correction technique is helpful to quantitative accuracy improvement. It is suggested to use CTAC+ SC+ RR in quantitative processing.

Objective To develop a specific trans-splicing intron ribozyme type Ⅰ-mediated dual reporter gene system (Rib53-Fluc-tk) for targeting CEA.Methods The novel CEA-targeting trans-splicing ribozyme with the downstream reporter system (Rib53-Fluc-tk) was constructed by genetic engineering technology.The trans-splicing reaction product was evaluated using the 131I-5-iodo-2'-fluro-l-beta-D-arabinofuranosy-luracil (FIAU) cellular uptake rates and the bioluminescence.Two-sample t test,the analysis of variance and the least significant difference (LSD) t test was performed for data analysis.Results The sequence of Rib53-Fluc-tk was proved by gene-sequencing test.Human MCF-7 breast cancer cells showed a high ratio of firefly luciferase/renilla luciferase (0.64±0.10,n =4).A 520 bp band of product existed,which matched with the predicted size using RNA from cells transfected with Rib53-Fluc-tk in MCF-7.Signals were detected by bioluminescence in human embryonic kidney 293T cells co-transfected with Rib53-Fluc-tk and pCDNA3.1-CEA.The labelling rate of 131I-FIAU was (64.02±4.79)％ (n =3).The radiochemical purity was (95.96± 1.07)％ (n=3),and the stability of the radiocompound remained high in human serum at least for 24 h.The uptake of 131I-FIAU in 293T cells transfected with Rib53-Fluc-tk was (0.31±0.01)％ (n=4),while it increased with the incubation time in 293T cells co-transfected with pCDNA3.1-CEA and Rib53-Fluc-tk and reached (1.40±0.06)％ at 4.5 h (F=1 007.29,t=136.34,both P＜0.01).Conelusions A novel and specific reporter gene in the cellular level was established.Taking advantage of trans-splicing reaction of the ribozyme,it could improve the specificity of the reporter gene imaging.

To investigate a new kind of tumor tracer 99mTc-YIGSR developed from a five amino structure (YIGSR) of the Laminin -chain,which can bind to the laminin receptors of tumor specifically, and radiolabeled with MAG3. (1) Preparation of the 99m Tc-YIGSR probe: with S-Acetly-NH3-MAG3as the chelator and with proper reductants YIGSR was labeled with 99mTc; (2) Cell culture and viability measurement: EAC was maintained in RPMI 1640 supplemented with calf serum; the trypan blue exclusion was applied to calculate the cell viability; (3) Study of the cell dynamic: The EACs uptake of 99mTc-YIGSR and99mTc-MIBI was observed at 37 ℃ and 22 ℃, respectively. (1)The labeling efficiencies of 99mTc-YIGSR and99mTc-MIBI were (62±3) % and (96±2) %, respectively; (2) The cell viability was declined with time of incubation; (3) At 37 ℃, the EACS uptake of 99mTc-YIGSR and99mTc-MIBI reached the peak of (43. 16±2.4) % and (24.4±1.8) % at 60min, respectively; and at 22 ℃, the highest uptake was (26.5±2.1) % and (9. 47±1.9) % at 60min, respectively. The in vitro study suggests that 99mTc-YIGSR is superior to 99mTc-MIBI in cell uptake and has potential value in tumor imaging.